1. Field of the Invention
The present invention relates to a compact camera module and the substrate thereof, and more particularly, to a compact camera module that can perform a self-check after a chip is attached and the substrate thereof.
2. Description of the Related Art
Compact camera modules (CCMs) are a type of compact image capturer and can be adopted in compact camcorders, digital still cameras or in electronic devices, such as cell phones, laptop computers and hand-held computers. The compact camera module substantially includes an image sensor chip disposed on a substrate and a barrel-shaped lens module with a lens. Rays of light can pass through the lens and reach the sensor area of the image sensor chip. The information of the captured image light is transformed into a digital format that can be saved in a storage medium. In order to avoid causing image distortion, it is required to precisely align the center of the sensor area of the sensor chip with the center of the lens module.
Referring to FIG. 1, a conventional substrate 110 for compact camera modules includes an upper surface 111 defining a chip-attached area 112, and a module-secured area 113. The chip-attached area 112 is substantially square and adapted to receive a sensor chip attached thereon. The module-secured area 113 surrounds the chip-attached area 112 and is adapted to carry a lens module mounted thereon. The area between the chip-attached area 112 and module-secured area 113 is provided with a plurality of connecting pads 114 and a plurality of fiducial marks 115. In accordance with compact camera module design, a check point 116 is defined in the chip-attached area 112 to calibrate the center of the sensor area of the sensor chip. The fiducial marks 115 are helpful to identify the location of the chip-attached area 112 and therefore can facilitate the attaching of the sensor chip to the chip-attached area 112. After the sensor chip is attached to the chip-attached area 112, the lens module is mounted on the module-secured area 113 to form the compact camera module. However, the use of the fiducial marks 115 to assist to attach the sensor chip to the chip-attached area 112 is apt to cause the center of the sensor area of the sensor chip not to be placed in the predetermined position and therefore cannot precisely align with the center of the lens module. This will cause the image distortion of the compact camera module. In addition, according to the conventional substrate design, the check point 116 fails to help to identify whether the center of the sensor area of the sensor chip deviates from its predetermined position in the chip-attached area 112 when the sensor chip has been attached to the chip-attached area 112. It is not uncommon to check the image performance of the lens module to identify whether the center of the sensor area of the sensor chip deviates from its predetermined position after the lens module has been mounted on the module-secured area 113. When the deviation of the sensor chip occurs, it is required to detach the sensor chip and lens module from the substrate 110 and then attach them back to the substrate 110 again according to the revised process parameters. After the sensor chip is attached to the substrate 110, it is unable to self-check the relative position of the sensor area of the sensor chip to substrate 110.
Accordingly, there exists a need to provide a substrate for compact camera modules to solve the aforesaid problems.